I have been setting up a server running Windows Server 2016 build 14300, and am trying to setup a WebDav server. It works fine if you access it from the local network, but it doesn't work if I try to access it from outside the network. I am running the server through 2 routers, (Router 1 -> Router 2 -> Server) I have tried just port forwarding, and setting up DMZ host (Router 1's DMZ Host - Router 2; Router 2's DMZ host - Server). On http://www.canyouseeme.org/, it shows both port 80 and 443 are open. I have tried accessing it with Windows File Explorer and CyberDuck, and they both aren't able to connect to it.
I have never done anything with IIS before, so I'm probably just doing something dumb. I have no idea what I’ve done wrong, so any help would be greatly appreciated. Thanks!